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Frontier Acela Fume Hood

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American Standard ASHRAE 110-1995<br />

The ASHRAE 110-1995 standard is a comprehensive method for<br />

evaluating the operator safety of fume hoods by determining<br />

quantitatively and repeatably how well the fume hood contains<br />

vapors released in the workzone. First published in 1985 and<br />

extensively revised in 1995, this standard employs a set of rigorous<br />

tests to evaluate hood performance:<br />

1. Airflow Visualization<br />

• Local and gross airflow visualization tests conducted to observe<br />

airflow patterns inside work chamber<br />

2. Face Velocity Measurements<br />

• Face velocity and uniformity tested at 100% and design sash<br />

opening position<br />

Typical measurement grid for 1.5m/5’ hood at<br />

457mm/18” sash opening<br />

1 2 3 4 5<br />

6 7 8 9 10<br />

275 275 275 275<br />

100 100<br />

110<br />

237 457<br />

110<br />

Grading<br />

Fail<br />

Poor<br />

Fair<br />

Good<br />

Observations<br />

Smoke observed escaping from the hood<br />

Reverse flow of smoke near opening<br />

Lazy flow into opening along boundary<br />

Observed potential for escape<br />

Some reverse flow, not necessarily at opening<br />

No visible escape<br />

No reverse flows<br />

Active flow streams into hood around boundary<br />

3. Tracer Gas Containment<br />

• Tracer gas containment test: SF6 released at 4L/min inside work<br />

chamber<br />

• Consists of 3 parts<br />

- Static gas leak conducted at<br />

3 positions (left, right, centre)<br />

- Face hood surface scan<br />

- Sash movement effect<br />

• Test criteria: leakage of less than<br />

0.05ppm as-manufactured<br />

3<br />

European Standard EN 14175<br />

EN 14175 is a harmonized European standard which supercedes<br />

the former national standards of Germany, the UK and France. A<br />

key element of the EN 14175, which is not present in the American<br />

ASHRAE 110 standard, is the robustness test, which simulates airflow<br />

disturbance in front of the hood.<br />

1. Inner Grid Test<br />

• A set of 9 sampling tubes are arranged in a 3 x 3 grid, at a distance<br />

of 30 mm from the measurement<br />

130mm<br />

400mm<br />

400mm<br />

2. Outer Grid Test<br />

• Outer grid testing measures the leakage<br />

of tracer gas across the entire sash<br />

opening<br />

• Sash is closed then opened during the<br />

test to investigate dynamic effect of sash<br />

movement<br />

3. Robustness Test<br />

• For the robustness test, a 0.4 x 1.9 m<br />

plate crosses the front of the fume hood<br />

at 1 m/s for 6 times<br />

• Provides an indication of the sensitivity<br />

of the fume hood towards external<br />

disturbances<br />

130mm<br />

plane<br />

• Leakage will be measured at 6 different grid positions<br />

Outer grid<br />

50 mm<br />

400 mm

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